Concentration measuring device and concentration measuring method

Abstract

This invention provides an apparatus for high-precision determination of protein concentration and urea-like substance concentration in dialysis fluid using spectrophotometry. The concentration measuring apparatus 100 includes: a measuring flow path 110; a first absorbance measuring unit 121 that measures the absorbance Y(λ1) of the dialysis fluid using light of a first wavelength λ1, which is attenuated primarily by urea-like substances; a second absorbance measuring unit 122 that measures the absorbance Y(λ2) of the dialysis fluid using light of a second wavelength λ2, which is attenuated by protein and urea-like substances; and a concentration calculation unit 152 that calculates the urea-like substance concentration X(U) based on the measured absorbance Y(λ1), and calculates the protein concentration X(ALB) based on the calculated urea-like substance concentration X(U) and the measured absorbance Y(λ2).

Description

Technical Field

[0001] This invention relates to a concentration measuring device and method for determining the concentration of urea-like substances and proteins in dialysis fluid. Background Technology

[0002] Blood purification therapy, which uses dialysate such as hemodialysis and hemodiafiltration, is performed on patients with renal insufficiency to remove excess water and waste products from their blood. Blood purification therapy is administered approximately three times a week, and its effectiveness is evaluated by the clearance rate of waste products, such as urea. Besides regular blood tests, a less burdensome, non-invasive method for determining solute clearance rates is known: measuring the concentration of solutes in the dialysis fluid. For example, Patent Document 1 describes a technique that involves irradiating the dialysis fluid with ultraviolet light and measuring its absorbance to determine the urea concentration.

[0003] In addition to the uremic toxin metabolites that are being removed, dialysis fluid also contains excessive leakage of albumin, a protein essential for the patient. Therefore, in addition to the solute concentration of uremic toxin metabolites, it is necessary to measure the concentration of proteins such as albumin. Albumin and other proteins have an absorbance peak around 280 nm; therefore, in general spectrophotometric measurements, ultraviolet light around 280 nm is used. However, when dialysis fluid is irradiated with ultraviolet light of this wavelength, in addition to proteins, absorption occurs due to urea-like substances such as uric acid and urea, making it difficult to accurately measure protein concentration (see [link to relevant documentation]). Figure 7 To this end, Patent Document 2 proposes a method for determining albumin concentration based on changes in absorbance of dialysis fluid caused by albumin removal.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Publication No. 2002-516722

[0007] Patent Document 2: Japanese Patent No. 6303555 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] In the albumin concentration determination method based on the aforementioned patent document 2, in order to reliably remove albumin leaked during dialysis and improve measurement accuracy, it is necessary to branch the drain line or limit the measurement flow rate. Therefore, there are concerns about the measurement device becoming larger and more complex.

[0010] Therefore, the purpose of this invention is to provide a measuring device that can accurately determine the concentration of proteins such as albumin and urea-like substances such as urea and uric acid in dialysis fluid using a simple structure and spectrophotometry.

[0011] Methods for solving problems

[0012] This invention relates to a concentration measuring device that measures the concentrations of urea-like substances removed by blood purification therapy using dialysis fluid and leaked proteins in dialysis drainage fluid. The device comprises: a measuring flow path for the flow of dialysis drainage fluid; a first absorbance measuring unit that measures the absorbance of the dialysis drainage fluid flowing through the measuring flow path using light of a first wavelength attenuated primarily by urea-like substances; a second absorbance measuring unit that measures the absorbance of the dialysis drainage fluid flowing through the measuring flow path using light of a second wavelength attenuated by proteins and urea-like substances; and a concentration calculation unit that calculates the concentrations of urea-like substances and proteins based on the absorbance measured by the first absorbance measuring unit and the absorbance measured by the second absorbance measuring unit. The concentration calculation unit calculates the urea-like substance concentration based on the absorbance measured by the first absorbance measuring unit and calculates the protein concentration based on the calculated urea-like substance concentration and the absorbance measured by the second absorbance measuring unit.

[0013] In addition, the preferred concentration measuring device also includes a storage unit, which pre-stores urea-like substance calibration information indicating the relationship between urea-like substance concentration and absorbance at the first wavelength, calibration information indicating the relationship between protein concentration and absorbance in a state containing urea-like substance at a specified concentration at the second wavelength, and multiple protein calibration information corresponding to multiple specified concentrations of urea-like substance. The concentration calculation unit calculates the urea-like substance concentration based on the absorbance measured by the first absorbance measuring unit and the urea-like substance calibration information stored in the storage unit, and calculates the protein concentration based on the protein calibration information of urea-like substance containing the calculated urea-like substance concentration and the absorbance measured by the second absorbance measuring unit.

[0014] In addition, it is preferable that the light of the first wavelength mentioned above is light in a band with a range of 300nm to 350nm.

[0015] In addition, it is preferred that the light of the second wavelength mentioned above has a wavelength range of 250 nm or more and less than 300 nm.

[0016] In addition, it is preferable that the aforementioned measuring flow path is connected to the pipeline for supplying dialysis fluid in the blood purification device, and that the aforementioned concentration calculation unit continuously measures the concentration of urea-like substances and protein concentration that change over time in the dialysis fluid continuously discharged from the aforementioned pipeline.

[0017] Furthermore, the present invention relates to a concentration measurement method, which measures the respective concentrations of urea-like substances removed by blood purification therapy using dialysis fluid and leaked proteins in the dialysis drain. The concentration measurement method comprises the following steps: a first absorbance measurement step, which measures the absorbance of the dialysis drain using light of a first wavelength attenuated primarily by urea-like substances; a second absorbance measurement step, which measures the absorbance of the dialysis drain using light of a second wavelength attenuated by proteins and urea-like substances; a first concentration calculation step, which calculates the concentration of urea-like substances based on the absorbance measured in the first absorbance measurement step; and a second concentration calculation step, which calculates the protein concentration based on the urea-like substance concentration calculated in the first concentration calculation step and the absorbance measured in the second absorbance measurement step.

[0018] In addition, it is preferable to pre-prepare urea-like substance calibration information indicating the relationship between urea-like substance concentration and absorbance at the aforementioned first wavelength, and calibration information indicating the relationship between protein concentration and absorbance in a state containing urea-like substance at a specified concentration at the aforementioned second wavelength, and multiple protein calibration information corresponding to multiple specified concentrations of urea-like substance. In the aforementioned first concentration calculation step, the urea-like substance concentration is calculated based on the absorbance measured in the aforementioned first absorbance measurement step and the aforementioned urea-like substance calibration information. In the aforementioned second concentration calculation step, the protein concentration is calculated based on the aforementioned protein calibration information of urea-like substance containing the concentration calculated in the aforementioned first concentration calculation step and the absorbance measured by the aforementioned second absorbance measurement step.

[0019] The effects of the invention

[0020] According to the present invention, by measuring the absorbance of the dialysis fluid using light of a first wavelength and light of a second wavelength respectively, the protein concentration and urea-like substance concentration in the dialysis fluid can be measured with high precision. Attached Figure Description

[0021] Figure 1 A diagram illustrating the concentration measuring device involved in this embodiment.

[0022] Figure 2 A block diagram illustrating the concentration measuring device is provided.

[0023] Figure 3A This diagram illustrates an example of the structure of the measuring section.

[0024] Figure 3B The diagram shows another example of the structure of the measuring section.

[0025] Figure 4 A diagram showing the relationship between the flow path used for measurement and the direction of illumination from the light source.

[0026] Figure 5A A graph showing the UV absorbance of albumin monomer solutions.

[0027] Figure 5B A graph showing the UV absorbance of uric acid monomer solutions.

[0028] Figure 6 A graph showing the UV absorbance of albumin in a solution containing uric acid.

[0029] Figure 7 A graph showing the light absorption characteristics of each solute contained in the dialysis fluid. Detailed Implementation

[0030] Hereinafter, a preferred embodiment of the concentration measuring device and concentration measuring method of the present invention will be described with reference to the accompanying drawings. The concentration measuring device according to this embodiment measures the changes over time in the concentration of urea-like substances containing urea and uric acid removed from the blood in hemodialysis, where dialysis is performed between blood and dialysate, as well as the concentration of proteins such as albumin leaking from the blood.

[0031] Reference Figures 1-4 The concentration measuring device 100 and the blood purification device 200 of this embodiment will be described.

[0032] Blood purification device

[0033] like Figure 1 As shown, the blood purification device 200 includes: a hemodialysis machine 210 such as a dialyzer and a hemodiafiltration filter; an arterial blood line L1; a venous blood line L2; a dialysate inlet line L3; a dialysate outlet line L4; a console 220 as a control device; and a dialysate drain line L5.

[0034] The hemodialyzer 210 is connected to an arterial blood line L1 and a venous blood line L2. Blood from the patient H is introduced into the hemodialyzer 210 via a blood pump P located in the arterial blood line L1. Additionally, the hemodialyzer 210 is connected to a dialysate inlet line L3 and a dialysate outlet line L4, thereby introducing dialysate into the hemodialyzer 210. Internally, solutes and water move between the blood and dialysate through the dialysis membrane, thus performing dialysis. In the dialysate outlet line L4, dialysate containing water and solutes flows from the blood, and this dialysate is discharged to the outside of the blood purification device 200 via the dialysate outlet line L5. The control console 220 controls the flow of blood and dialysate. In this way, dialysis treatment is performed through the blood purification device 200. The control console 220 includes a display unit 230, which displays various information indicating the status of the dialysis treatment.

[0035] <Concentration Measurement Device>

[0036] like Figure 2 As shown, the concentration measuring device 100 of this embodiment includes: a measuring unit 140; a control device 150; and a display unit 160 for displaying the measurement results.

[0037] like Figure 2 As shown in Figure 3, the measuring unit 140 comprises a flow path 110 for measuring fluid from dialysis, a measuring section 120, and a measuring section housing 130. In this embodiment, as shown... Figure 1 The example shown depicts the measurement unit 140 positioned in the dialysate drain line L5, but it can also be positioned in the dialysate outlet line L4. By connecting the measurement unit 140 to the dialysate outlet line L4 or dialysate drain line L5 of the blood purification device 200, the concentrations of urea-like substances and protein in the dialysate continuously discharged from the dialysate outlet line L4 or dialysate drain line L5 over time can be continuously measured.

[0038] The measurement flow path 110 is connected to the dialysate outlet line L4 or the dialysate drain line L5 of the blood purification device 200, configured to allow the dialysate drained from the test subject to flow. In this embodiment, the measurement flow path 110 is connected to the dialysate drain line L5. For example, such as... Figure 3A As shown, the measuring flow path 110 is provided to penetrate the central portion of the measuring unit housing 130. Furthermore, a through hole 131 is formed in the measuring unit housing 130, orthogonal to the measuring flow path 110. Figure 3AIn the example shown, the measuring flow path 110 consists of a flat flow path 111 that penetrates the central portion of the measuring unit housing 130, a circular plate-shaped flow path component 112 disposed in the through hole 131 to separate the light-emitting unit 120E and the light-receiving unit 120R (described later) from the dialysis drain, and a sealing gasket 114 that blocks the gap between the flow path component 112 and the measuring unit housing 130. Additionally, as... Figure 3B As shown, the measuring flow path 110 can also be constructed from a tubular flow path 113. Regarding the flat flow path 111, the flow path component 112, and the tubular flow path 113, at least the portion sandwiched between the light-emitting unit 120E and the light-receiving unit 120R is formed of a material that is transmissive to ultraviolet light. Examples of materials that are transmissive to ultraviolet light include quartz glass, PTFE (polytetrafluoroethylene), PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), and other fluorinated resins.

[0039] The measuring unit 120 is used to measure the concentration of urea-like substances, including urea and uric acid, and the concentration of proteins such as albumin in the dialysis fluid. Figure 3A or Figure 3B As shown, the measuring unit 120 includes a light-emitting unit 120E and a light-receiving unit 120R.

[0040] like Figure 4 As shown, the light-emitting unit 120E and the light-receiving unit 120R are arranged in the measuring section housing 130 such that they sandwich the measuring flow path 110 and are opposite to each other. Holes are formed in the measuring section housing 130 to respectively fix the light-emitting unit 120E and the light-receiving unit 120R. Furthermore, the irradiation direction of the light from the light-emitting unit 120E is arranged approximately orthogonally to the flow direction of the dialysate in the measuring flow path 110. Additionally, the distance X between the light-emitting unit 120E and the light-receiving unit 120R can be adjusted within the range of 3 mm ≤ X ≤ 12 mm.

[0041] The light-emitting unit 120E includes a first light-emitting part 121E with a light emission wavelength band of 300nm to 350nm for irradiating light of the first wavelength, and a second light-emitting part 122E with a light emission wavelength band of 250nm to 300nm for irradiating light of the second wavelength. In ultraviolet light between 300nm and 350nm, attenuation based on proteins such as albumin occurs almost nonexistent; attenuation mainly occurs based on urea-like substances containing urea and uric acid. Conversely, in ultraviolet light between 250nm and 300nm, attenuation occurs due to various solutes such as proteins and urea-like substances (see reference). Figure 7 ).

[0042] The light-receiving unit 120R is equipped with a photodiode having a light-receiving wavelength band of 300nm to 350nm as a first light-receiving unit 121R for receiving light of a first wavelength irradiated by the first light-emitting unit 121E, and a photodiode having a light-receiving wavelength band of 250nm to 300nm as a second light-receiving unit 122R for receiving light of a second wavelength irradiated by the second light-emitting unit 122E. It should be noted that when using photodiodes with a light-receiving wavelength band of 250nm to 350nm as the first light-receiving unit 121R and the second light-receiving unit 122R, a single photodiode can also be used.

[0043] The first absorbance measuring unit 121 is composed of a first light-emitting part 121E and a first light-receiving part 121R. This first absorbance measuring unit 121 can measure the absorbance of dialysate at a first wavelength of 300 nm to 350 nm, which is attenuated primarily by urea-like substances. For example, a wavelength of around 300 nm, which is significantly attenuated due to uric acid, can also be used as the first wavelength.

[0044] The second absorbance measuring unit 122 comprises a second light-emitting unit 122E and a second light-receiving unit 122R. This unit can measure the absorbance of dialysate at a second wavelength (between 250 nm and 300 nm), which is attenuated by urea-like substances and proteins. Ideally, the second wavelength should be around 280 nm, which is the wavelength at which the absorbance of albumin reaches its peak.

[0045] The control device 150 includes: a control unit 151 for controlling the operation of the measuring unit 120; a concentration calculation unit 152 for calculating the concentration; and a storage unit 153. The control device 150 may be configured to include the main body of the concentration measuring device 100, or it may be integrated with the control console 220 of the blood purification device 200.

[0046] The control unit 151 controls the first light-emitting unit 121E and the second light-emitting unit 122E by driving them with a certain load ratio. Specifically, in order to prevent the output light from the first and second light-emitting units from interfering with each other, the control is performed by staggering the timing of driving each light-emitting diode.

[0047] The concentration calculation unit 152 determines the concentration of urea-like substances and protein concentration based on the absorbance measured by the measuring unit 120. The specific method for calculating the concentration is explained in detail below.

[0048] Storage unit 153 stores calibration information for urea-like substances and calibration information for multiple proteins.

[0049] The urea-like substance calibration information is information that shows the relationship between the concentration of urea-like substance and absorbance at the first wavelength.

[0050] The protein calibration information represents the relationship between protein concentration and absorbance when a urea-like substance of a specified concentration is present at a second wavelength. Furthermore, in this embodiment, the storage unit 153 stores multiple protein calibration information corresponding to cases containing multiple concentrations of urea-like substance.

[0051] The display unit 160 has the function of displaying numerical values ​​and graphs of calculated results, cumulative results, and indicators related to urea dialysis volume, such as Kt / V (K: clearance rate, t: dialysis time, V: body fluid volume), for urea-like substance concentration, protein concentration, or dialysis volume. The display unit 160 can be installed on the main body of the concentration measuring device 100, or it can be the display unit 230 of the control console 220. Alternatively, the control device 150 can be connected to a personal computer terminal, tablet computer terminal, etc., and the display unit of these terminals can be used as the display unit 160. Figure 1 As shown, in this embodiment, the display unit 230 of the console 220 is configured as the display unit 160.

[0052] <Existing methods for concentration measurement>

[0053] Use specific examples to illustrate existing concentration determination methods.

[0054] Protein concentration was determined in dialysis fluid containing urea-like substances and proteins. Therefore, it was considered to use 280 nm ultraviolet light, which increases the absorbance of albumin, to measure the absorbance.

[0055] For example, when measuring the absorbance of monomeric solutions of albumin and uric acid by irradiating them with 280 nm ultraviolet light, such as... Figure 5A As shown, in the albumin concentration range of approximately 800 mg / dL, or as... Figure 5B As shown, high-precision measurement can be performed in the uric acid concentration range of approximately 5 mg / dL. Specifically, the solute concentration is set as X, and the absorbance as Y. Figure 5A and Figure 5B When the slope of the standard curve is set to A, the concentration can be calculated using the relationship X = Y / A (Equation 1).

[0056] However, as Figure 7 As shown, in actual dialysis drainage, 280nm ultraviolet light is attenuated not only due to the protein component containing albumin, but also due to urea-like substances such as urea and uric acid, which are essential for Kt / V calculations. Therefore, it is speculated that even if dialysis drainage is irradiated with 280nm ultraviolet light and its absorbance is measured, it will be difficult to determine protein concentration with high precision.

[0057] As an example, when a simulated albumin solution containing a certain amount of uric acid was irradiated with 280 nm ultraviolet light and the absorbance was measured, the following results were obtained: Figure 6 The results are shown. Thus, as uric acid concentration increases, the measurable range of albumin narrows, and the slope of the standard curve gradually changes, therefore Equation 1 cannot be applied. Therefore, even if the dialysate is irradiated with 280 nm ultraviolet light and the absorbance is measured, the concentrations of urea-like substances and protein in the dialysate cannot be calculated separately.

[0058] <Concentration Measurement Method of the Invention>

[0059] The concentration determination method of this embodiment includes: a first absorbance determination step, which uses light of a first wavelength, which is attenuated mainly by urea-like substances, to determine the absorbance of the dialysate; a second absorbance determination step, which uses light of a second wavelength, which is attenuated by protein and urea-like substances, to determine the absorbance of the dialysate; a first concentration calculation step, which calculates the concentration of urea-like substances; and a second concentration calculation step, which calculates the protein concentration.

[0060] In the first absorbance measurement step, light of a first wavelength λ1, which is attenuated by a larger proportion of urea-like substances compared to protein, is used to measure the absorbance Y(λ1) of the dialysate by the first absorbance measurement unit 121. In this embodiment, ultraviolet light of about λ1 = 300 nm is used as an example of the first wavelength light.

[0061] In the second absorbance measurement step, the absorbance Y(λ2) of the dialysate is measured by the second absorbance measurement unit 122 using light of a second wavelength λ2 that is attenuated by protein and urea-like substances. In this embodiment, ultraviolet light of about λ2 = 280 nm is used as an example of light of the second wavelength λ2.

[0062] In the first concentration calculation step, the concentration of the urea-like substance is calculated from the absorbance measured in the first absorbance measuring unit 121. In the first wavelength λ1, the proportion of protein-based attenuation is smaller than the proportion of urea-like substance-based attenuation, so it can be processed as a monomeric solution, and the concentration of the urea-like substance can be calculated from the measured absorbance Y(λ1).

[0063] Specifically, the first absorbance measuring unit 121 pre-calculates information about a urea sample standard curve (urea sample calibration information) with a slope B representing the relationship between the urea sample concentration X(U) and the absorbance Y(λ1) at the first wavelength λ1, and stores it in the storage unit 153. Here, the relationship X(U)=Y(λ1) / B holds true, so the concentration calculation unit 152 can calculate the urea sample concentration X(U) based on the slope B (urea sample calibration information) of the urea sample standard curve stored in the storage unit 153 and the measured absorbance Y(λ1).

[0064] In the second concentration calculation process, the protein concentration X (ALB) is calculated based on the absorbance Y (λ2) measured by the second absorbance measuring unit 122 and the calculated urea-like substance concentration X (U).

[0065] Specifically, using the second absorbance measuring unit 122, the absorbance is measured at multiple urea sample concentrations X(U1), X(U2), ..., X(U... N In the process, the slopes C1, C2, ..., C are calculated in advance. N Information on a protein standard curve (protein calibration information) showing the relationship between protein concentration X (ALB) and absorbance Y (λ2) at a second wavelength λ2 is stored in storage unit 153. For example, the protein standard curve is prepared with a urea-like substance concentration X (U) at a scale of 1 mg / dL, within a range of 0.0 mg / dL to 10.0 mg / dL. N Only the slope C needs to be determined. N This allows for the calculation of protein concentration X (ALB) with sufficiently high accuracy.

[0066] Concentration calculation unit 152 calculates the concentrations X(U1), X(U2), ..., X(U) of urea-like substances stored in storage unit 153. N Among them, the urea-like substance concentration X(U) that is closest to the calculated urea-like substance concentration X(U) is selected. N ), and select the slope C of the corresponding protein standard curve. N It should be noted that when selecting the calculated urea-like substance concentration X(U) and a urea-like substance concentration X(U) with a similar value... N When calculating the urea concentration X(U), round the first decimal place and select the closest value for the urea concentration X(U). N ).

[0067] Here, X(ALB) = Y(λ2) / C N Equation 3 holds true, therefore the concentration calculation unit 152 can use the slope C of the protein standard curve at the calculated urea-like substance concentration X(U) as the basis for its calculation. N The protein concentration X (ALB) is calculated from the measured absorbance Y (λ2).

[0068] The concentration measuring device and concentration measuring method according to this embodiment achieve the following effects.

[0069] (1) The concentration measuring device 100 includes: a measuring flow path 110; a first absorbance measuring unit 121, which measures the absorbance Y(λ1) of the dialysate flowing through the measuring flow path 110 using light of a first wavelength λ1, which is mainly attenuated by urea-like substances; a second absorbance measuring unit 122, which measures the absorbance Y(λ2) of the dialysate flowing through the measuring flow path 110 using light of a second wavelength λ2, which is attenuated by protein and urea-like substances; and a concentration calculation unit 152, which calculates the absorbance Y(λ2) of the dialysate flowing through the measuring flow path 110 based on the first absorbance measurement. The absorbance Y(λ1) measured by the first absorbance measuring unit 121 and the absorbance Y(λ2) measured by the second absorbance measuring unit are used to calculate the urea-like substance concentration X(U) and the protein concentration X(ALB). In the concentration calculation unit 152, the urea-like substance concentration X(U) is calculated based on the absorbance Y(λ1) measured by the first absorbance measuring unit 121, and the protein concentration X(ALB) is calculated based on the calculated urea-like substance concentration X(U) and the absorbance Y(λ2) measured by the second absorbance measuring unit 122. Therefore, by measuring the absorbance Y(λ1) and Y(λ2) of the dialysate using light of the first wavelength λ1 and the second wavelength λ2 respectively, the protein concentration X(ALB) and the urea-like substance concentration X(U) in the dialysate can be measured with high precision. In addition, unlike in the past, there is no need to prepare a membrane for removing protein (albumin) and multiple measuring units, thus simplifying the structure of the device.

[0070] (2) The concentration measuring device 100 includes a storage unit 153, which pre-stores information (slope B) of a urea sample standard curve representing the relationship between the urea sample concentration X(U) and absorbance Y(λ1) at the first wavelength λ1, and information representing multiple urea sample concentrations X(U1), X(U2), ..., X(U3) at the second wavelength λ2. N Information on multiple protein standard curves relating protein concentration X (ALB) to absorbance Y (λ2) (slopes C1, C2, ..., C...) N In the concentration calculation unit 152, the urea-like substance concentration X(U) is calculated based on the absorbance Y(λ1) measured by the first absorbance measuring unit 121 and the information (slope B) of the urea-like substance standard curve stored in the storage unit 153. The concentration is then calculated based on the information (slope C1, C2, ..., C...) of the protein standard curve corresponding to the calculated urea-like substance concentration X(U). NThe protein concentration X (ALB) is calculated using the absorbance Y (λ2) measured by the second absorbance measuring unit 122. Therefore, the urea-like substance concentration X (U) can be calculated with high precision using the absorbance Y (λ1) measured at a first wavelength λ1 where the attenuation is less due to protein. Furthermore, the protein concentration X (ALB) can be calculated with high precision using the protein standard curve corresponding to the calculated urea-like substance concentration X (U) and the absorbance Y (λ2) measured at a second wavelength λ2 where the attenuation is due to protein and urea-like substance.

[0071] (3) The measuring flow path 110 is made to connect to the tubing (dialysis fluid outlet tubing L4 or dialysis fluid drainage tubing L5) of the blood purification device 200 for the flow of dialysis fluid, and the concentrations of urea-like substances X (U) and protein concentration X (ALB) in the dialysis fluid continuously discharged from the tubing (L4 or L5) are continuously measured over time. Thus, during dialysis treatment, the concentrations of urea-like substances X (U) and protein concentration X (ALB) in the dialysis fluid can be measured over time, so the treatment effect of dialysis can be analyzed even without performing invasive examinations such as regular blood tests.

[0072] The preferred embodiments of the concentration measuring device and concentration measuring method of the present invention have been described above, but are not limited thereto. In the above embodiments, as an example, a structure in which the concentration measuring device is installed on a blood purification device is shown, but a structure in which the concentration measuring device and the blood purification device are integrated into one unit is also possible.

[0073] In addition, in the above embodiments, the measuring unit of the concentration measuring device of the present invention is shown to be arranged in the dialysate drain line, but it can also be arranged in the dialysate outlet line.

[0074] Furthermore, the concentration measuring device and concentration measuring method of the present invention are not limited to blood purification devices equipped with hemodialysis machines, but can also be applied to the concentration measurement of urea-like substances and proteins in the dialysis fluid during peritoneal dialysis.

[0075] Explanation of reference numerals in the attached figures

[0076] 100 Concentration Measuring Device

[0077] 110 Flow path for measurement

[0078] 120 Measurement Department

[0079] 130 Measuring section housing

[0080] 140 Measurement Units

[0081] 150 (Concentration measuring device) Control device

[0082] 151 Control Department

[0083] 152 Concentration Calculation Department

[0084] 153 Storage Department

[0085] 160 Display Section

[0086] 200 Blood Purification Devices

[0087] 210 Hemodialysis machine

[0088] 220 Control console (control device)

[0089] 230 Display Section

[0090] L1 arterial side blood vessels

[0091] L2 venous side blood tubing

[0092] L3 Dialysis fluid inlet tubing

[0093] L4 Dialysis fluid outlet tubing

[0094] L5 Dialysis fluid drain line

Claims

1. A concentration measuring device for measuring the concentrations of urea-like substances and leaked proteins removed through blood purification therapy using dialysis fluid in the dialysis drain. The concentration measuring device includes: Flow path for measuring the flow of dialysis fluid; The first absorbance measuring unit uses light of a first wavelength, which is mainly attenuated by urea-like substances, to measure the absorbance of the dialysate flowing through the measuring flow path. The second absorbance measuring unit uses light of a second wavelength, attenuated by protein and urea-like substances, to measure the absorbance of the dialysate flowing through the measuring flow path; and The concentration calculation unit calculates the concentration of urea-like substance and protein concentration based on the absorbance measured by the first absorbance measuring unit and the absorbance measured by the second absorbance measuring unit. in, The concentration calculation unit calculates the urea-like substance concentration based on the absorbance measured by the first absorbance measuring unit, and calculates the protein concentration based on the calculated urea-like substance concentration and the absorbance measured by the second absorbance measuring unit. The first absorbance measuring unit includes: a first light-emitting unit that illuminates the measuring flow path with light of the first wavelength; and a first light-receiving unit that is arranged opposite to the first light-emitting unit, sandwiching the measuring flow path, and receiving light of the first wavelength illuminated by the first light-emitting unit. The second absorbance measuring unit includes: a second light-emitting unit that illuminates the measuring flow path with light of the second wavelength; and a second light-receiving unit that is arranged opposite to the second light-emitting unit, sandwiching the measuring flow path, and receiving light of the second wavelength illuminated by the second light-emitting unit. The light of the first wavelength is light in the range of 300nm to 350nm. The second wavelength of light is light with a wavelength range of 250 nm or higher and lower than 300 nm.

2. The concentration measuring device as claimed in claim 1, further comprising a storage unit, wherein the storage unit pre-stores urea-like substance calibration information representing the relationship between urea-like substance concentration and absorbance at the first wavelength, and calibration information representing the relationship between protein concentration and absorbance at the second wavelength containing a specified concentration of urea-like substance, and multiple protein calibration information corresponding to multiple specified concentrations of urea-like substance. The concentration calculation unit calculates the urea-like substance concentration based on the absorbance measured by the first absorbance measuring unit and the urea-like substance calibration information stored in the storage unit, and calculates the protein concentration based on the protein calibration information of the urea-like substance containing the calculated urea-like substance concentration and the absorbance measured by the second absorbance measuring unit.

3. The concentration measuring device as described in claim 1 or 2, wherein, The measurement flow path is connected to the tubing in the blood purification device that supplies the dialysis fluid. The concentration calculation unit continuously measures the concentration of urea-like substances and protein concentration in the dialysis fluid continuously discharged from the pipeline over time.

4. Concentration determination method: The concentration of urea-like substances and leaked proteins removed by blood purification therapy using dialysis fluid in the dialysis wastewater is determined. The concentration determination method includes the following steps: The first absorbance measurement step uses light of the first wavelength, which is mainly attenuated by urea-like substances, to measure the absorbance of the dialysate flowing through the measurement flow path. The second absorbance measurement step uses light of a second wavelength, which is attenuated by protein and urea-like substances, to measure the absorbance of the dialysate flowing through the measurement flow path. The first concentration calculation step calculates the concentration of the urea-like substance based on the absorbance measured in the first absorbance measurement step. The second concentration calculation step calculates the protein concentration based on the urea-like substance concentration calculated in the first concentration calculation step and the absorbance measured in the second absorbance measurement step. In the first absorbance measurement step, light of a first wavelength from the first light-emitting unit is irradiated into the measurement flow path. A first light-receiving unit, positioned to sandwich the measurement flow path and opposite the first light-emitting unit, receives the light of the first wavelength irradiated from the first light-emitting unit. In the second absorbance measurement step, light of a second wavelength from the second light-emitting unit is irradiated into the measurement flow path. A second light-receiving unit, positioned to sandwich the measurement flow path and opposite the second light-emitting unit, receives the light of the second wavelength irradiated from the second light-emitting unit. The light of the first wavelength is light in the range of 300nm to 350nm. The second wavelength of light is light with a wavelength range of 250 nm or higher and lower than 300 nm.

5. The concentration determination method as described in claim 4, wherein, Urea-like substance calibration information is pre-prepared, representing the relationship between urea-like substance concentration and absorbance at the first wavelength, and protein calibration information is pre-prepared, representing the relationship between protein concentration and absorbance at the second wavelength containing a specified concentration of urea-like substance, and multiple protein calibration information corresponding to multiple specified concentrations of urea-like substance. In the first concentration calculation step, the concentration of the urea sample is calculated based on the absorbance measured in the first absorbance measurement step and the calibration information of the urea sample. In the second concentration calculation step, the protein concentration is calculated based on the protein calibration information of the urea-like substance whose concentration was calculated in the first concentration calculation step, and the absorbance measured by the second absorbance measurement step.

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